View Compilation Error

0_0_18697234_17480.cpp: In function 'int main()':
0_0_18697234_17480.cpp:79:31: error: unable to find numeric literal operator 'operator""n'
             if(cont==50||i==i*2n)
                               ^
0_0_18697234_17480.cpp:79:31: note: use -std=gnu++11 or -fext-numeric-literals to enable more built-in suffixes